Multichannel Schwinger theory

The multichannel model functions wosq and wlsq are real-valued continuum solutions of the model problem, in a A -matrix formalism. They are normalized to the matrix Wronskian condition 

The multichannel generalization of the principal value Green function is a linear 

If / 7(r) is a vector of functions, one for each open channel, that are regular at the coordinate origin and quadratically integrable, then 

Using the matrix Wronskian condition, the proof is the same as for the singlechannel problem. 

This multichannel matrix Green function determines a multichannel Lippmann-Schwinger equation 

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